Browsing a complex JSON

first of all, excuse me for my English, I'm French.

I am coming to you because I have a problem. I would like help browsing a complex JSON object with a loop in Javascript (because it generates itself with JOINTJS) but I am not being able to do it. I can do it manually by json [ "cells"] ["7"] ["attrs"] ["text"] ["text"]. Here is an example of JSON for one element: